Surface Checking on White Oak - When to worry?

Hoping some of the air drying folks can chime in a potential problem I’m noticing on by recently sawn white oak

I recently purchased some fairly freshly milled quarter sawn white oak and intend to air dry it in my basement. I’ve purchased air dried and KD lumber from various places before but this is one of the first times I’m doing the dying. The wood purchased in 3” x 3” x 8’ and 4” x 3” x 10’ and quarter sawn.

I did what I thought was an appropriate amount of research both on this site and elsewhere about air drying and the potential challenges of oak. It it seemed that the amount of time it would take to dry was the biggest negative and I was ok with that. I knew oak was an especially slow drying species from trying to scrounge up firewood for my wood burning stove as well.

The wood is stacked and stickered in my basement. The wood was cut a few days before I could get to it but I did apply a coat of anchorseal to the endgrain as soon as I got it. I also put double stickers close to the end to further fight end grain checking. I’m in New England so it’s sub-freezing this time of year and very dry. Technically, my basement isn’t heated but it’s probably in the 50-60 range most of the winter depending on the weather and time of day. I have a dehumidifier in the space but it rarely if ever runs this time of year and it’s in the other end of the space. The wood has been in my basement for ~2wks now and I’m getting notable surface checking. Yes there is some checking on the ends but nothing I’m going to lose sleep over. I’m more concerned that I’ll have case hardening issues or be forced to machine off a meaningful amount of width.

I have read that some surface checking is to be expected and that it may close itself up with time as the moisture from the inside migrates outword and things level off a bit, but found very little regarding what point how much should cause concern. Any thoughts? I’ll try to get a pic or two up later but I’m also just generally wondering how normal surface checking is. Is there something I should do / have done? Is this mostly an issue b/c it’s oak?

Any insight would be appreciated Thanks

10 replies so far

AVS, I have never dried wood, but I use a lot of white oak. I have seen more surface checking than I would like. The checks tend to go through the wood at an angle and they can be difficult to see. I once made a sofa table and didn’t notice the check until I was applying the finish. The finish is a bit rough where the check meets the surface, but is barely noticeable 5-6 years later. You might be getting the checking because you moved the wood from the very dry and cold out doors to the warmer, damper basement. It is best to dry wood very slowly and especially so with white oak. I would have left it out doors under a minimal covering, but too late for that now. Good luck.

THe thing with white oak is that you want to dry it slow. If the outside drys first it becomes like a case and the inside will honeycomb. the cracking on the outside is one of the first signs of this. A friend of mine (He’s been working wood since the 1940s) piles his boards about 4 inches apart and puts the next layer 90 deg to it and 4 inches apart. (His stacks are 8foot by 8 foot.) cover it with a tarp, throw 2 sheets of plywood on top and stack junk on it. Leave it in the barn for 10 years (or more.) It’s wonder stock if I can get him to part with it.

If it’s cracking you should probably cover it with something to slow down the drying. Also make sure you paint the ends of the boards. Figure a year drying per inch of thickness, and you want it to take that long. If you can leave it longer it only tends to relax any inner stress in the wood. Don’t be in a hurry.

(When you go to use it, If the cracks are little hairline things, drizzle them with thin super glue and let it dry. no one will ever know.)

A dry basement is a poor place to dry 3” thick white oak. It will dry too fast there. Many bad things will happen. Better to take it outside and put it under a shed or build a roof over it (old tin, plywood, etc.). When air drying, the wood dries during the day, and at night when the humidity gets high, it naturally conditions the wood allowing the shell and core to better come to equilibrium. I would get it out of the basement as soon as possible.

As has been mentioned, the standard procedure for air drying is to stack and sticker it. Expose I to the wind, but shelter it from the rain. Once it reaches equilibrium around 15% moisture content, then it can be kiln dried.

A couple observations specific to white oak beams and billet stock. Square (or nearly square) stock is very likely to warp, twist, and check. In my opinion, there is no such thing as quartersawn 3” x 3” stock. It is just as much flatsawn as it is quartersawn. I usually don’t pay for the square stock that is left over from milling QSWO, as the sawyer usually throws it in with my order. I use it to weight down stacks of lumber, and use it for short workpieces.

On quartersawn lumber, say 5/4 that is 8-9” wide, I sometimes see checking on one end of the board. It usually occurs where the grain transitions from quartersawn to flatsawn. The instances I have seen have not been casehardening, just some surface checking where the grain changes direction.

Once the lumber is ready for kiln drying, remember to get good airflow over the stack.Post some pictures and maybe we can help with the issues you’re having.Good luck with it.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

A dry basement is a poor place to dry 3” thick white oak. It will dry too fast there. Many bad things will happen. Better to take it outside and put it under a shed or build a roof over it (old tin, plywood, etc.). When air drying, the wood dries during the day, and at night when the humidity gets high, it naturally conditions the wood allowing the shell and core to better come to equilibrium. I would get it out of the basement as soon as possible.

- WDHLT15

The challenge of the situation is I’m honestly not sure my basement is meaningfully different than outdoors except that it’s marginally warmer. I have very little reason to believe the relative humidity is lower than outside. It certainly isn’t in other seasons – hence the dehumidifier. It isn’t running this time of year though. When it’s 30s and sunny outside like it was today it’s probably ~60 in my basement. At the same time though, there isn’t any airflow. Therefore, I wouldn’t think it would dry any faster in my basement than my garage or shed. Any shy of me adding a humidifier I’m at a loss for what to do.